Sayyiduna Abdullah bin Amr al-As (may Allah be pleased with him) narrates this statement of the Noble Prophet (peace and blessings be upon him): "The most beloved prayer to Allah Almighty is the prayer of Sayyiduna Dawud (peace be upon him); he used to sleep for half the night, offer voluntary prayers for one third of the night, and then sleep for one sixth of the night. And the most beloved way of fasting to Allah Almighty is the way of fasting of Sayyiduna Dawud (peace be upon him); he used to fast one day and not fast the next day."
Hadith Referenceصحیح ابن حبان / كتاب الصلاة / 2590
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «الإرواء» (451 و 945)، «صحيح الترغيب» (618)، «صحيح أبي داود» (2098): ق.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط مسلم